CD4 and infection: The observation that IL-2c-expanded ILC2s could provide significant, but limited, immunity to a primary infection with H. polygyrus in the absence of CD4+ T cells (Figure 3) was in stark contrast to the ability of ILC2s to drive complete expulsion of N. brasiliensis following similar IL-2c treatment.11 We therefore explored whether ILC2s could instead be supporting the development of adaptive immune responses in vivo, and in particular whether ILC2-derived IL-4 contributed to TH2 differentiation in vivo following H. polygyrus infection.